An anonymous airline passenger is being hailed as a hero after she stopped a potential sexual assault by glancing at a fellow passenger’s text messages.

A preschool teacher was on a flight from Seattle, Washington to San Jose, California when she noticed that the man in the row in front of her was sending explicit texts about sexually abusing children.

Since the texts were in an especially large font on a sizable phone, the teacher was able to snap pictures of the texts and use them as evidence against the suspected predator: 56-year-old Michael Kellar of Tacoma, Washington.

According to news sources, Kellar is being held at the Santa Clara County Jail, while Burnworth is being held at the Pierce County jail, both of whom are being charged with attempted child molestation and solicitation of sex crimes.

“It’s kind of mind-blowing,” San Jose sex-crimes Detective Nick Jourdenais told the Mercury News about the anonymous passenger. “She gets on a plane, a normal citizen minding her business. A couple of hours later, she’s intervening on quite possibly the most traumatic thing children can go through. This was life-altering for them.”